Abstract :
Radiowave sensors based on planar transmission lines are widely used to design autodyne devices and systems for short-range radiolocation. The sensors are small, lightweight and cost-effective with high sensitivity. The possibilities of the sensors are especially expanded when based on modern active elements that use the GaAs structure with the interlinear transmission of the electrons (MAP diodes or diodes using the Gunn effect). As the resonance system, slot and coplanar transmission lines are used. The autodyne modules M55314 ("Tigel-5") and "Tigel-8" are made on short sections of slot transmission lines. In the 5 mm range the frequency (55-63 GHz) is fixed and in the 8 mm (33.4-36.0 GHz) range the frequency is modulated in the chain by a varactor in an interval less than +200 MHz from the carrier frequency. The design of the above-mentioned sensors with the high mechanical durability (shocks and vibration) is connected with the design of military (small-size radio-exploders, self-directing heads, etc.) as well as civil equipment (transport electronics, microwave radiography, control and measuring equipment, medicine etc.). Equipment made with the use of the given construction provide the following working modes: autodyne frequency transformation, autogeneration mode with AM modulation; multiplication of generation frequency, and autogeneration with changing frequency. The obtained results of the tests as well as the ease of construction, cost-effectiveness, high security and low cost of the proposed autodyne modules should allow their wide use.
Keywords :
Gunn diodes; III-V semiconductors; electric sensing devices; gallium arsenide; millimetre wave detectors; millimetre wave diodes; radio direction-finding; 33.4 to 63 GHz; AM modulation; EHF; FM modulation; GaAs structure; Gunn diodes; M55314; MM-wave sensors; Tigel-5; Tigel-8; autodyne devices; autodyne frequency transformation; autogeneration mode; civil equipment; coplanar transmission lines; frequency modulation; high mechanical durability; high sensitivity; military equipment; planar transmission lines; radiowave sensors; resonance system; short-range radiolocation; slot transmission lines; varactor; Coplanar transmission lines; Diodes; Frequency; Gallium arsenide; Geographic Information Systems; Gunn devices; Modular construction; Planar transmission lines; Sensor systems; Vibration measurement;